-Adrenergic Suppression of Progesterone-Induced Luteinizing Hormone Surge in Ovariectomized, Estrogen-Primed Rats

Abstract
In ovariectomized, estrogen-primed animals isoproterenol can interrupt a progesterone-induced LH [luteinizing hormone] surge already in progress and lower blood LH to control levels. The noradrenergic influence may contain both .alpha.-adrenoceptor (stimulatory) and .beta.-adrenoceptor (inhibitory) components and an LH surge is triggered only when the balance is tipped in favor of the .alpha.-adrenoceptor component, presumably by the modulatory action of ovarian steroids.